This invention relates generally to sod harvesting equipment and more specifically to a sod harvester guidance system and a method and apparatus for transferring sod rolls while maintaining the integrity of the transferred sod rolls.
The concept of sod harvesting is old in the art. Typically, a sod slab is cut free from a sod field. The slab is then rolled up into a cylindrical roll that is transferred to a pallet by a sod pickup mechanism. If the sod rolls are xe2x80x9csmall rollsxe2x80x9d, the sod rolls can be manually transferred to a sod delivery truck that delivers the sod to the area where the sod rolls are to be laid. If the sod rolls are xe2x80x9cbig rollsxe2x80x9d, it is necessary to use equipment to both lift and transfer the sod rolls. Numerous devices are available for mechanizing portions of the sod harvesting and delivering process. For example, U.S. Pat. No. 5,230,602 shows a sod roll stacker for stacking rows of small rolls. Still other devices are available for cutting and rolling both small rolls and big rolls.
One of the problems with handling sod rolls is the loose or free end of the sod roll can be located in any angular position of the sod roll which can result in at least partially unwinding of the sod roll during handling, which makes it difficulty to transfer the sod roll, while maintaining the integrity of the sod roll. Typically, the sod rolls are formed by elevating a sod slab along an elevator while a top stationary member engages the edge of the sod to roll the sod slab into a roll. The sod roll is then delivered to a trough on a bed where the sod rolls are then transferred to a pallet for delivery to the work site. The transferring of the sod rolls from one mechanism to another mechanism can result in partially unwinding of the sod roll causing difficulties in picking up the sod roll as well as tearing the sod roll. In addition to damage to the sod roll, it usually requires the operator to stop the machine and clear the machine of any damaged sod rolls.
The sod harvesting system of the present invention also includes a steering mechanism to maintain the sod harvester in proper alignment with the sod to be cut with the steering mechanism including an ultrasonic sensor.
A sod harvester having a sod rolling device is shown in our copending patent application Titled Sod Harvester, Ser. No. 09/236,170 filed Jan. 25, 1999 and is incorporated herein by reference. The present invention provides a guidance system a method and apparatus for transferring sod rolls from one mechanism to another while maintaining the integrity of the transferred sod rolls.
Briefly, the present invention comprises a method of transferring sod rolls while maintaining the integrity of the sod rolls by maintaining a sod roll in pressure contact with another sod roll while the sod roll is being transferred from one sod roll handling mechanism to another sod roll handling mechanism and a sod harvester guidance system using a sonic transducer for maintaining a full cut.